Effectiveness of higher doses of botulinum toxin to induce healing in patients with chronic anal fissures

Randomized clinical trial of botulinum toxin injection for pain relief in patients with thrombosed external haemorrhoids

BACKGROUND

Thrombosed external haemorrhoids are one of the most frequent anorectal emergencies. They are associated with swelling and intense pain. Internal sphincter hypertonicity plays a role in the aetiology of the pain. This study evaluated the efficacy and safety of an intrasphincteric injection of botulinum toxin for pain relief in patients with thrombosed external haemorrhoids.

METHODS

Thirty patients with thrombosed external haemorrhoids who refused surgical operation were randomized into two groups. Patients received an intrasphincteric injection of either 0.6 ml saline or 0.6 ml of a solution containing 30 units botulinum toxin. Anorectal manometry was performed before treatment and 5 days afterwards.

RESULTS

After 5 days of treatment, the maximum resting pressure fell in both groups, but was significantly lower in the botulinum toxin group (P = 0.004). Pain intensity was significantly reduced within 24 h of botulinum toxin treatment (P < 0.001), but only after 1 week in the placebo group (P = 0.019).

CONCLUSION

A single injection of botulinum toxin into the anal sphincter seems to be effective in rapidly controlling the pain associated with thrombosed external haemorrhoids, and could represent an effective conservative treatment for this condition.

REGISTRATION NUMBER

NCT00717782 (http://www.clinicaltrials.gov).

[Fistulas and fissures. Part II: fissures]

Fissures in ano are linear ulcers situated in the anal canal and extending from the dentate line to the margin of the anus. They cause pain and spasms. Diagnosis is made by the history alone. Local medical treatment might consist of topical 0.4% glycerol trinitrate or 2% calcium blocker. In case of therapy resistance, botulinum toxin injection into the internal sphincter is an effective but expensive alternative with encouraging results. If medical treatment fails, then operation has to be recommended. As lateral internal sphincterotomy represents poses a clear danger to continence, fissurectomy combined with the excision of skin tags and any anal papilla is now the operative treatment of choice.

Botulinum toxin: description of injection techniques and examination of controversies surrounding toxin diffusion

The benefits derived from botulinum toxin (BTX) injections may be negated by unintentional weakness of adjacent uninjected muscles. Such weakness may be the result of inaccurate targeting, or diffusion of BTX to surrounding muscles. Several techniques, using electromyographic, endoscopic or imaging guidance are purported to increase the accuracy of targeting. Diffusion of BTX is thought to be influenced by factors such as dose, concentration, injectate volume, number of injections, site and rate of injection, needle gauge, muscle size, muscular fascia, distance of needle tip from the neuromuscular junction, and protein content of the BTX formulation. This article describes techniques that aim to increase the accuracy of BTX injections and examines the controversies surrounding diffusion of BTX following injection.

Botulinum toxin A for the treatment of chronic anal fissure

Since its introduction for the treatment of strabismus, botulinum toxin (BoNT) has been increasingly used in the treatment of several disorders with excessive or inappropriate muscle contractions. The therapeutic effects of BoNT occur through the temporary chemodenervation caused by the injection into the local target muscle or skin. Modulation of muscle relaxation may be achieved by varying the dose of BoNT solution injected; most adverse effects are transient. Indeed, botulinum neurotoxin has been used to selectively weaken the internal anal sphincter as a treatment for chronic anal fissure in several randomized, controlled trials and open-label studies. The use of botulinum neurotoxin seems to be an effective and safe approach for the treatment of chronic anal fissure, particularly in patients at high risk for incontinence.

Medical and surgical treatment of chronic anal fissure: a prospective study

The aim of this prospective study was to assess the efficacy of different medical treatments and surgery in the treatment of chronic anal fissure (CAF). From 1/04 to 09/06, 156 patients with typical CAF completed the study. All patients were treated with 0.2% nitroglycerin ointment (GTN) or anal dilators (DIL) for 8 weeks. If no improvement was observed after 8 weeks, patient was assigned to the other treatment or a combination of the two. Persisting symptoms after 12 weeks or recurrence were indications for either botulinum toxin injection into the internal sphincter and fissurectomy or lateral internal sphincterotomy (LIS). During the follow-up (19 +/- 8 months), healing rates, symptoms, incontinence scores, and therapy adverse effects were prospectively recorded. Overall healing rates were 65.3 and 96.3% after GTN/DIL or BTX/LIS. Healing rate after GTN or DIL were 39.8 and 46%, respectively. Thirty-six patients (23.1%) responded to further medical therapy. Fifty-four patients (34.6%) underwent BTX or LIS. Healing rate after BTX was 81.8%. LIS group showed a 100% healing rate with no morbidity and postoperative incontinence. In conclusion, although LIS is far more effective than medical treatments, BTX injection/fissurectomy as first line treatment may significantly increase the healing rate while avoiding any risk of incontinence.

Nonsurgical approaches for the treatment of anal fissures

Chronic anal fissure (CAF) is usually associated with internal anal sphincter spasm, the relief of which is central to provide fissure healing. The treatment for CAF has undergone a transformation in recent years from surgical to medical. Both the approaches share the common goal of reducing the spasm. Though surgical treatment has a high success rate, it can permanently impair fecal continence in a large number of patients. Smooth muscle relaxation seems to be a novel way by which more than 60% of the patients can be cured with the topical use of the agents. This treatment is in addition to the normalization of stools mostly. Smooth muscle relaxation is well tolerated, can be administered on an outpatient basis, does not cause any lesion of the continence organ, and subsequently, does not lead to any permanent latent or apparent fecal incontinence. This review encompasses various agents that are used for smooth muscle relaxation. In addition, it describes various clinical studies reported in the literature with their success rates and side effects.

Randomized clinical trial comparing botulinum toxin injections with 0.2 per cent nitroglycerin ointment for chronic anal fissure

BACKGROUND

In recent years treatment of chronic anal fissure has shifted from surgical to medical. This study compared the ability of two non-surgical treatments-botulinum toxin injections and nitroglycerin ointment-to induce healing in patients with idiopathic anal fissure.

METHODS

One hundred adults were assigned randomly to receive treatment with either type A botulinum toxin (30 units Botox or 90 units Dysport) injected into the internal anal sphincter or 0.2 per cent nitroglycerin ointment applied three times daily for 8 weeks.

RESULTS

After 2 months, the fissures were healed in 46 (92 per cent) of 50 patients in the botulinum toxin group and in 35 (70 per cent) of 50 in the nitroglycerin group (P=0.009). Three patients in the botulinum toxin group and 17 in the nitroglycerin group reported adverse effects (P<0.001). Those treated with botulinum toxin had mild incontinence to flatus that lasted 3 weeks after treatment but disappeared spontaneously, whereas nitroglycerin treatment was associated with transient, moderate-to-severe headaches. Nineteen patients who did not have a response to the assigned treatment crossed over to the other therapy.

CONCLUSION

Although treatment with either topical nitroglycerin or botulinum toxin is effective as an alternative to surgery for patients with chronic anal fissure, botulinum toxin is the more effective option.

New techniques in the treatment of common perianal diseases: stapled hemorrhoidopexy, botulinum toxin, and fibrin sealant

There have been several recent advances in the treatment of common perianal diseases. Stapled hemorrhoidopexy is a procedure of hemorrhoidal fixation, combining the benefits of rubber band ligation into an operative technique. The treatment of anal fissure has typically relied upon internal sphincterotomy; however, it carries a risk of incontinence. The injection of botulinum toxin represents a new form of sphincter relaxation, without division of any sphincter muscle; morbidity is minimal and results are promising. For the treatment of fistula in a fistulotomy remains the gold standard, however, it carries significant risk of incontinence. Use of fibrin sealant to treat fistulae has been met with variable success. It offers sealing of the tract, and then provides scaffolding for native tissue ingrowth.

Non surgical therapy for anal fissure

BACKGROUND

Because of the disability associated with surgery for anal fissure and the risk of incontinence, medical alternatives for surgery have been sought. Most recently, pharmacologic methods that relax the anal smooth muscle, to accomplish reversibly what occurs in surgery, have been used to obtain fissure healing.

OBJECTIVES

To assess the efficacy and morbidity of various medical therapies for anal fissure.

SEARCH STRATEGY

Search terms include "anal fissure randomized". Timing from 1966 to May 2006. Further details of the search below.

SELECTION CRITERIA

Studies in which participants were randomized to a non-surgical therapy for anal fissure. Comparison groups may include an operative procedure, an alternate medical therapy or placebo. Chronic fissure, acute fissure and fissure in children are included in the review. Atypical fissures associated with inflammatory bowel disease or cancer or anal infection are excluded.

DATA COLLECTION AND ANALYSIS

Data were abstracted from published reports and meeting abstracts, assessing method of randomization, blinding, "intention to treat" and drop-outs, therapies, supportive measures (applied to both groups), dosing and frequency and cross-overs. Dichotomous outcome measures included Non-healing of the fissure (a combination of persistence and recurrence), and Adverse events (including incontinence, headache, infection, anaphylaxis). Continuous outcome measures included measures of pain relief and anorectal manometry.

MAIN RESULTS

48 different comparisons of the ability of medical therapies to heal anal fissure have been reported in 53 RCTs. Eleven agents were used (nitroglycerin ointment (GTN), isosorbide dinitrate, Botulinum toxin (Botox), diltiazem, nifedipine (Calcium channel blockers or CCBs), hydrocortisone, lignocaine, bran, minoxidil, indoramin, and placebo) as well as anal dilators and surgical sphincterotomy.GTN was found to be marginally but significantly better than placebo in healing anal fissure (48.6% vs. 37%, p < 0.004), but late recurrence of fissure was common, in the range of 50% of those initially cured. Botox and CCBs were equivalent to GTN in efficacy with fewer adverse events. No medical therapy came close to the efficacy of surgical sphincterotomy, though none in these RCTs was associated with the risk of incontinence.

AUTHORS' CONCLUSIONS

Medical therapy for chronic anal fissure, acute fissure and fissure in children may be applied with a chance of cure that is marginally better than placebo, and, for chronic fissure in adults, far less effective than surgery.

Randomized clinical trial of botulinum toxin plus glyceryl trinitrate vs. botulinum toxin alone for medically resistant chronic anal fissure: overall poor healing rates

PURPOSE

This study was designed to assess whether addition of glyceryl trinitrate to botulinum toxin improves the healing rate of glyceryl trinitrate-resistant fissures over that achieved with botulinum toxin alone.

METHODS

Patients were randomized between botulinum toxin plus glyceryl trinitrate (Group A) and botulinum toxin plus placebo paste (Group B). Patients were seen at baseline, four and eight weeks, and six months. The primary end point was fissure healing at eight weeks. Secondary end points were symptomatic relief, need for surgery, side effects, and reduction in maximum resting and squeeze pressures.

RESULTS

Thirty patients were randomized. Two-thirds of patients had maximum anal resting pressures below or within the normal range at entry to the study. Healing rates in both treatment groups were disappointing. There was a nonsignificant trend to better outcomes in Group A compared with Group B in terms of fissure healing (47 vs. 27 percent), symptomatic improvement (87 vs. 67 percent), and resort to surgery (27 vs. 47 percent).

CONCLUSIONS

There is some evidence to suggest that combining glyceryl trinitrate with botulinum toxin is superior to the use of botulinum toxin alone for glyceryl trinitrate-resistant anal fissure. The poor healing rate may reflect the fact that many of the patients did not have significant anal spasm at trial entry.

Efficacy and safety of botulinum toxin a injection compared with topical nitroglycerin ointment for the treatment of chronic anal fissure: a prospective randomized study

OBJECTIVES

To evaluate the efficacy and safety of botulinum toxin A injection compared with topical nitroglycerin ointment for the treatment of chronic anal fissure (CAF).

METHODS

Fifty outpatients with CAF were randomized to receive either a single botulinum toxin injection (30 IU Botox) or topical nitroglycerin ointment 0.2% b.i.d. for 2 wk. If the initial therapy failed, patients were assigned to the other treatment group for a further 2 wk. If CAF still showed no healing at wk 4, patients received combination therapy of botulinum toxin and nitroglycerin for 4 additional wk. Persisting CAF at wk 8 was treated according to the investigator's decision. Healing rates, symptoms, and side effects of the therapy were recorded at wk 2, 4, 8, 12, and 24 after randomization.

RESULTS

The group initially treated with nitroglycerin showed a higher healing rate of CAF (13 of 25, 52%) as compared with the botulinum toxin group (6 of 25, 24%) after the first 2 wk of therapy (p < 0.05). At the end of wk 4, CAF healed in three additional patients, all receiving nitroglycerin after initial botulinum toxin injection. Mild side effects occurred in 13 of 50 (26%) patients, all except one were on nitroglycerin.

CONCLUSIONS

Nitroglycerin ointment was superior to the more expensive and invasive botulinum toxin injection for initial healing of CAF, but was associated with more but mild side effects.

Botulinum toxin for gastrointestinal disorders: therapy and mechanisms

Botulinum toxin has gained widespread acceptance as a treatment option for various spastic gastrointestinal disorders such as achalasia, gastroparesis, sphincter of Oddi dysfunction, chronic anal fissures, and pelvic floor dyssnergia, despite the lack of strong evidence supporting its use in many of these diseases. This review summarizes the trials investigating the use of BoNT since it was first utilized as a treatment in achalasia. BoNT has proven to be safe, but long-term efficacy in many disorders has not been observed, primarily due to is relatively short duration of action. BoNT may be most useful in confirming a diagnosis which can lead to a more definitive treatment modality. Furthermore, its safety profile allows it to be a useful alternative in patients who are at high risk for invasive procedures.

Toxine botulique et fissure anale chronique

Lateral internal sphincterotomy is widely used in the treatment of chronic anal fissure. However, it is associated with a high rate of irreversible incontinence. For this reason the botulinum toxin has become a medical means of reversible sphincterotomy. Indeed, this neurotoxin induces relaxation of the smooth internal anal sphincter lasting one to three months after one injection. We reviewed the published studies about the use of this technique in the management of chronic anal fissure. Healing occurred in more than 70% of fissures without irreversible incontinence. Although further studies are needed to determine the best modalities of administration, especially due to the remaining significant recurrence rate, this toxin may be a valuable treatment for chronic anal fissure in the future.

Chronic anal fissure: 1994 and a decade later--are we doing better?

BACKGROUND

Debate exists regarding whether the use of topical agents and Botox injections are as efficacious as sphincterotomy for the treatment of chronic anal fissure.

METHODS

A retrospective review was performed to assess changes in management and outcomes of chronic anal fissure care in a community based colorectal practice between the individual years 1994 and 2003.

RESULTS

Forty-seven patients in 1994 underwent lateral partial internal sphincterotomy and had a 100% healing rate. Thirty-nine patients were treated in 2003, with 32 undergoing Botox injection and 7 undergoing sphincterotomy initially. Of the Botox patients, 35% had recurrence, and 7 subsequently required sphincterotomy. Ultimate healing rates in 2003 were 97%. Time to heal was markedly prolonged in 2003 compared with 1994. Complication rates were similar, and there was no lifestyle-altering incontinence.

CONCLUSIONS

Our review documents a significant change in the community approach to chronic fissure management. The addition of multiple treatment modalities prolongs time to healing from initial evaluation, but they allowed 72% of patients to avoid the need for permanent sphincter division while maintaining ultimate rates of healing.

Botulinum toxin in dermatology - beyond wrinkles and sweat

Botulinum toxin (BTX) types A and B have been used with success in cosmetic dermatology and hyperhidrosis treatment. The present review focuses on other uses of BTX in dermatology. Discussed in particular are the available data on BTX in inflammatory diseases, proctology, and some other indications. From studies in various types of eczema, it seems that BTX-A not only acts as a potent inhibitor of acetylcholine but also as an inhibitor of substance P and of glutamate as well. By those mechanisms, BTX-A may be antipruritic, which may help explain the benefits of BTX-A in lichen simplex and dyshidrotic hand eczema. In Hailey-Hailey disease, facial eccrine hidrocystomas, salivary fistulas, and intrinsic rhinitis, BTX-A blocks the secretion of sweat/saliva/mucus. BTX-A has important applications in proctology where it has become the most powerful nonsurgical therapy for anal fissures. In proctalgia fugax and after hemorrhoidectomy, BTX-A is analgesic. Current treatment applications of BTX-A and its limitations are reviewed in this paper.

Inhibitory effects of sildenafil citrate on the tonus of isolated dog internal anal sphincter

PURPOSE

Although the exact pathogenesis of anal fissure is not known, hypertonicity of the internal anal sphincter might be involved in its pathogenesis as main event. To gain information about possible usefulness of the novel, smooth-muscle-relaxing drug, sildenafil, in chronic anal fissure, we investigated the effect of sildenafil citrate on acetylcholine-induced contractility of internal anal sphincter isolated from dogs.

METHODS

Internal anal sphincter strips were taken from German shepherd dogs and suspended in a tissue bath filled with Krebs solution at 37 degrees C (pH 7.4) continuously bubbled with 95 percent oxygen and 5 percent carbon dioxide, and isometric contractions were recorded. Contractions were evoked by 10 muM acetylcholine, and the effects of different concentrations of sildenafil citrate (0.1, 0.3, and 1 mM) on the isometric tension of each internal anal sphincter strip were examined. The statistical significance was analyzed by one-way analysis of variance.

RESULTS

Pretreatment with sildenafil citrate (0.1 mM) attenuated contractile response to acetylcholine (n = 3), which were significantly weak compared with the maximum contractile response to the acetylcholine alone (610 +/- 110 mg vs. 2,825.17 +/- 416 mg; n = 12; P < 0.05). Sildenafil citrate also significantly inhibited the acetylcholine-induced contractions in a dose-dependent manner when applied after.

CONCLUSIONS

This experimental in vitro study showed that sildenafil citrate relaxes acetylcholine stimulated contractions of isolated dog internal anal sphincter. This may be of importance for raising the possibility that sildenafil cit-rate may have future potential in the treatment of chronic anal fissure. Further studies are needed for a conclusive decision on possible usefulness of sildenafil citrate in patients with chronic anal fissure.

Prospective manometric assessment of botulinum toxin and its correlation with healing of chronic anal fissure

INTRODUCTION

The efficacy and pharmacokinetics of botulinum toxin for chronic anal fissure continues to be debated. Addressing both issues we prospectively assessed the manometric impact of botulinum toxin on internal anal sphincter pressure, correlating this impact with chronic anal fissure healing.

METHODS

Sixty patients with chronic fissures were assessed. Fifty-seven patients had a total of 20 units of botulinum toxin injected into the intersphincteric groove at four o'clock and eight o'clock. Patients were prospectively assessed with a linear analog pain score, bleeding score, clinical fissure score, modified St. Mark's continence score, and anorectal manometry. Each parameter was reassessed two weeks following treatment and again at three months.

RESULTS

Fifty-six patients (30 female), median age 43 (range, 17-80) years, were followed for a median of five (range, 3-15) months with fissure healing assessed 12 weeks after treatment. Physical healing and symptom control were dependent on the baseline maximum anal resting pressure and baseline fissure score (P = 0.003, P = 0.009, respectively). Although maximum anal resting pressure fell by 17 (mean, range, 0-71) percent, pressure reduction did not correlate with clinical outcome (P > 0.2). Seventeen patients reported a mean 17 percent increase in continence score. There was no correlation between deterioration in continence and baseline or subsequent reduction in maximum anal resting pressure.

CONCLUSION

Patients with Grade 1 lower-pressure fissures are more likely to heal following treatment with 20 units of botulinum toxin. Healing does not appear to be dependent on a reduction in maximum anal resting pressure.

Tratamiento de la fisura anal crónica

Chronic anal fissure is a common benign anorectal problem in Western countries that substantially impairs the patient's life. Consequently, a rapid and effective solution is required. We reviewed the various treatments for chronic anal fissure described in the literature, with the aim of establishing a therapeutic protocol. We recommend surgical sphincterotomy (preferably open or closed lateral sphincterotomy) as the first therapeutic approach in patients with chronic anal fissure. However, we prefer the use of chemical sphincterotomy (preferably botulinum toxin) in patients aged more than 50 years old and in those with previous incontinence, risk factors for incontinence (previous anal surgery, multiple vaginal births, diabetes, inflammatory bowel disease, etc.), or without anal hypertonia, despite the higher recurrence rate with medical treatments, since this procedure avoids the greater risk of residual incontinence described in the literature with surgical sphincterotomy in this group of patients.

Surgical (close lateral internal sphincterotomy) versus chemical (botulinum toxin) sphincterotomy as treatment of chronic anal fissure

BACKGROUND AND OBJECTIVE

The aim of this prospective randomized trial was to compare the effectiveness and morbidity of surgical vs chemical sphincterotomy in the treatment of chronic anal fissure after a 3-year follow-up period.

PATIENTS AND METHOD

Eighty patients with chronic anal fissure were treated either with close lateral internal sphincterotomy (group 1) or with chemical sphincterotomy with 25 U botulinum toxin injected into the internal sphincter (group 2).

RESULTS

Overall healing was 90% in the close sphincterotomy group and 45% in the toxin botulinum group (p < 0.001). There was a group of patients with clinical factors (duration of disease over 12 months and presence of a sentinel pile before treatment) associated with a higher recurrence of anal fissure. Final percentage of incontinence was 5% in the close sphincterotomy group and 0% in the botulinum toxin group (p > 0.05). All incontinent patients were aged more than 50 years.

CONCLUSIONS

We recommend surgical sphincterotomy as the first therapeutic approach in patients with clinical factors of recurrence. However, we recommend the use of botulinum toxin in patients older than 50 years or with associated risk factors of incontinence, despite the higher rate of recurrence, since it avoids the greater risk of incontinence seen with surgery.

[Manometric factors associated with recurrence in botulinum toxin treatment for chronic anal fissure]

INTRODUCTION AND AIM

To evaluate the effectiveness of botulinum toxin in the treatment of chronic anal fissure after long-term follow-up and establish the manometric factors related to recurrence.

PATIENTS AND METHOD

We performed a prospective study in 50 consecutive patients with chronic anal fissure who were treated with 25 U botulinum toxin injected into the internal sphincter. Clinical and manometric parameters were recorded until the fourth year of follow-up.

RESULTS

There was a tendency to progressive recurrence over time (54% at 4 years) associated with manometric factors indicating hyperexcitability of the internal anal sphincter (persistently elevated mean resting pressure, percentage of time with slow waves, and number of patients or percentage of time with ultra-slow waves after treatment).

CONCLUSIONS

Treatment of chronic anal fissure with botulinum toxin leads to long-term cure in less than 50% of patients. In patients with manometric factors related to recurrence, this treatment is insufficient for definitive cure.

Surgical versus chemical (botulinum toxin) sphincterotomy for chronic anal fissure: long-term results of a prospective randomized clinical and manometric study

BACKGROUND

The aim of this prospective randomized trial was to compare the effectiveness and morbidity of surgical versus chemical sphincterotomy in the treatment of chronic anal fissure after a 3-year follow-up.

METHODS

Eighty patients with chronic anal fissure were treated by whether open lateral internal sphincterotomy (group 1) or chemical sphincterotomy with 25 U botulinum toxin injected into the internal sphincter (group 2). Clinical and manometric results were analyzed.

RESULTS

Overall healing was 92.5% in the open sphincterotomy group and 45% in the toxin botulinum group (P<.001). There is a group of patients with clinical (duration of disease >12 months and presence of a sentinel pile before treatment) and manometric factors (persistently elevated mean resting pressure, % of time presence of slow waves, and number of patients or the time presence ultra slow waves after treatment) associated with a higher recurrence of anal fissure. The final percentage of incontinence was 5% in the open sphincterotomy group and 0% in the botulinum toxin group (P>.05).

CONCLUSION

We recommend surgical sphincterotomy as the first therapeutic approach in patients with clinical and manometric factors of recurrence. We prefer the use of botulinum toxin in patients older than 50 years or with risk factors for incontinence, despite the higher rate of recurrence, since it avoids the greater risk of incontinence in the surgical group.

Long-term results of botulinum toxin for the treatment of chronic anal fissure: prospective clinical and manometric study

BACKGROUND

The aim of this prospective trial was to analyse the effectiveness and morbidity of chemical sphincterotomy in the treatment of chronic anal fissure after a 3-year follow-up.

METHODS

One hundred consecutive patients with chronic anal fissures were treated by chemical sphincterotomy with 25 U botulinum toxin injected into the internal sphincter. Clinical and manometric results were recorded.

RESULTS

No major complications were found; initial incontinence at the 2-month review (6%) spontaneously reversed at 6 months. There was a tendency of progressive recurrence over time, with an overall healing after 3 years of 47%. We found a group of patients with clinical (symptoms longer than 12 months and presence of a sentinel pile before treatment) and manometric factors (persistently elevated mean resting pressure, percentage of time with slow waves, and number of patients or percentage of time with ultra slow waves after treatment) associated with a higher recurrence of anal fissures.

CONCLUSION

Since it avoids the greater risk of incontinence associated with surgical sphincterotomy, we recommend the use of botulinum toxin as the first therapeutic approach for patients with chronic anal fissure and risk factors for incontinence; despite the higher rate of recurrence associated with this treatment. In patients with factors related to recurrence, re-injection with higher doses of botulinum toxin or complementary medical-surgical treatment should be considered.

Treating chronic anal fissure with botulinum neurotoxin

Recent reports confirm that the management of chronic anal fissure has undergone extensive re-evaluation during the past few years. This rejuvenation of interest is attributable to the application of neurochemical treatment, which has contributed to the tendency to treat the disease on an outpatient basis. The use of botulinum neurotoxin seems to be a promising and safe approach for the treatment of chronic anal fissure, particularly in patients at high risk for incontinence. Indeed, botulinum neurotoxin has been successfully used selectively to weaken the internal anal sphincter as a treatment for chronic anal fissure. It is also more efficacious than nitrate therapy, and is not related to the patient's willingness to complete treatment.

A systematic review of medical therapy for anal fissure

PURPOSE

This is a meta-analysis of randomized, controlled trials to assess the efficacy and morbidity of medical therapies for anal fissure.

METHODS

Medline and the Cochrane Controlled Trials Register and the Cochrane Colorectal Cancer Review Groups Controlled Trials Register were searched using the terms "anal fissure randomized" from 1966 to 2002. Studies in which participants were randomized to a nonsurgical therapy for anal fissure were the focus of this review. Comparison groups included an operative procedure, an alternate medical therapy, or placebo. Chronic fissure, acute fissure, and fissure in children were included in the review, however, atypical fissure associated with inflammatory bowel disease, cancer, or anal infection were excluded. Data were abstracted from published reports and meeting abstracts, assessing method of randomization, blinding, "intention to treat" and dropouts, therapies, supportive measures, dosing and frequency, and crossovers. Outcome measures included nonhealing of the fissure and adverse events.

RESULTS

Twenty one different comparisons of medical therapies to heal anal fissure have been reported in 31 trials, including 9 agents-glyceryl trinitrate, isosorbide dinitrate, botulinum toxin, diltiazem, nifedipine, hydrocortisone, lidocaine, bran, placebo-as well as anal dilators and surgical sphincterotomy. Glyceryl trinitrate was favored in the analysis over placebo (odds ratio = 0.55, 95 percent confidence interval, 0.41-0.74). After excluding two studies from analysis because of placebo response rates >2 standard deviations below the mean for all studies, the advantage of glyceryl trinitrate over placebo was no longer statistically significant (odds ratio = 0.78; 95 percent confidence interval, 0.56-1.08). Nifedipine and diltiazem did not differ from glyceryl trinitrate in their ability to cure fissure (0.66; 0.22-2.01). Botulinum toxin compared with placebo showed no significant efficacy (0.75; 0.32-1.77), and was also no better than glyceryl trinitrate (0.48; 0.21-1.10). Surgery was more effective than medical therapy in curing fissure (0.12; 0.07-0.22).

CONCLUSIONS

Medical therapy for chronic anal fissure, acute fissure, and fissure in children may be applied with a chance of cure that is only marginally better than placebo, and for chronic fissure, far less effective than surgery.

Botulinum toxin injection versus lateral internal sphincterotomy in the treatment of chronic anal fissure: a non-randomized controlled trial

BACKGROUND

Although lateral internal sphincterotomy is the gold-standard treatment for chronic anal fissure, intrasphincteric injection of botulinum toxin seems to be a reliable new option. The aim of this non-randomized study is to compare the effect of lateral internal sphincterotomy and botulinum toxin injection treatments on the outcome and reduction of anal sphincter pressures in patients with chronic anal fissure.

METHODS

Patients with chronic anal fissure were treated with either botulinum toxin injection or lateral internal sphincterotomy by their own choice. Maximal resting pressure and maximal squeeze pressure measurements were performed before and 2 weeks after treatments by anal manometry. Patients were followed for fissure relapse during 14 months.

RESULTS

Twenty-one consecutive outpatients with posterior chronic anal fissure were enrolled. Eleven patients underwent surgery and ten patients received botulinum toxin injection treatment. Before the treatment, anal pressures were found to be similar in both groups. After the treatment, the maximal resting pressures were reduced from 104 +/- 22 mmHg to 86 +/- 15 mmHg in the surgery group (p < 0.05) and from 101 +/- 23 mmHg to 83 +/- 24 mmHg in the botulinum toxin group (p < 0.05). The mean maximal squeeze pressures were reduced from 70 +/- 27 mmHg to 61 +/- 32 mmHg (p > 0.05) in the surgery group, and from 117 +/- 62 mmHg to 76 +/- 34 (p < 0.01) in the botulinum toxin group. The fissures were healed in 70 percent of patients in the botulinum group and 82 percent in the surgery group (p > 0.05). There were no relapses during the 14 months of follow up.

CONCLUSION

Lateral internal sphincterotomy and botulinum toxin injection treatments both seem to be equally effective in the treatment of chronic anal fissure.

Botulinum neurotoxin to treat chronic anal fissure: results of a randomized "Botox vs. Dysport" controlled trial

BACKGROUND

Botulinum neurotoxin induces healing in patients with idiopathic fissure. The optimal dosage is not well established.

AIM

To compare the efficacy and tolerability of two different formulations of type A botulinum neurotoxin, and to provide more evidence with regard to the choice of dosage regimens.

METHODS

Symptomatic adults with chronic anal fissure were enrolled in a randomized study. The outcome of each group was evaluated clinically, and by comparing the pressure of the anal sphincters before and after treatment.

RESULTS

Fifty patients received injections of 50 units of Botox formulation (group I), and 50 patients received injections of 150 units of Dysport toxin (group II). One month after injection, 11 patients in group I and eight in group II had mild incontinence of flatus. At the 2-month evaluation point, 46 patients in group I and 47 patients in group II had a healing scar. In group I patients, the mean resting anal pressure was 41.8% lower, and the maximum voluntary squeeze pressure was 20.2% lower, than the baseline value. In group II patients, the resting anal pressure and maximum voluntary squeeze pressure were 60.0 +/- 12.0 mmHg and 71.0 +/- 30.0 mmHg, respectively. There were no relapses during an average of about 21 months of follow-up.

CONCLUSIONS

Botulinum neurotoxin may be considered an effective treatment in patients with chronic anal fissure. The efficacy and tolerability of the two different formulations of botulinum neurotoxin were indistinguishable.

Treatment with botulinum neurotoxin of gastrointestinal smooth muscles and sphincters spasms

Local injections of botulinum neurotoxin are now considered an efficacious treatment for neurological and non-neurological conditions. One of the most recent achievements in the field is the observation that botulinum neurotoxin provides benefit in diseases of the gastrointestinal tract. Botulinum neurotoxin inhibits contraction of gastrointestinal smooth muscles and sphincters; it has also been shown that the neurotoxin blocks cholinergic nerve endings in the autonomic nervous system, but it does not block nonadrenergic responses mediated by nitric oxide. This aspect has further promoted the interest to use botulinum neurotoxin as a treatment for overactive smooth muscles, such as the anal sphincters to treat anal fissure and outlet-type constipation, or the lower esophageal sphincter to treat esophageal achalasia. Knowledge of the anatomical and functional organization of innervation of the gastrointestinal tract is a prerequisite to understanding many features of botulinum neurotoxin action on the gut and the effects of injections placed into specific sphincters. This review presents current data on the use of botulinum neurotoxin to treat diseases of the gastrointestinal tract and summarizes recent knowledge on the pathogenesis of disorders of the gut due to a dysfunction of the enteric nervous system.

Review article: botulinum toxin in the therapy of gastrointestinal motility disorders

Since 1980, botulinum toxin has been employed for the treatment of various voluntary muscle spastic disorders in the fields of neurology and ophthalmology. More recently, botulinum toxin has been proved to be effective in the therapy of dyskinetic smooth muscle disorders of the gastrointestinal tract. Achalasia and anal fissure are the gastrointestinal disorders in which botulinum toxin therapy has been most extensively investigated. Botulinum toxin is the best treatment option for achalasia in patients whose condition makes them unfit for pneumatic dilation or surgery. In anal fissure, botulinum toxin is highly effective and may become the treatment of choice. In the future, botulinum toxin application in the gastrointestinal tract will be extended to many other gastrointestinal disorders, such as non-achalasic motor disorders of the oesophagus, dysfunction of Oddi's sphincter, achalasia of the internal anal sphincter and others. This article describes the mechanism of action, rationale of employment, indications and side-effects of botulinum toxin application in smooth muscle disorders of the gastrointestinal tract, and compares the results of different techniques of botulinum toxin therapeutic application.

[Digestive tract and botulinum toxin]

INTRODUCTION

the aim of this work was to check literature to assess botulinum toxin injection efficacy in gastrointestinal motor disorders with special emphasis on controlled clinical trials.

METHODS

literature was carried out with the Medline data bank.

RESULTS

seventy three articles in French and in English including a recent general review were retained. Comparative clinical trials only concerned achalasia and anal fissure. The other gastrointestinal motor disorders only gave rise to open non-controlled trials assessed on clinical end points.

DISCUSSION

this review of literature helps to determine usefulness and safety of Botulinum toxin injection in the treatment of esophageal achalasia and anal fissure. The main limitation is its brief duration of action. Studies concerning the others spastic motor disorders are based on unknown physiopathology and controlled trials are required to assess its efficacy.

CONCLUSION

botulinum toxin is increasingly used for gastrointestinal motor disorders with worthwhile results. Its efficacy has been yet established for only two disorders : it has a valuable palliative role in achalasia and may be curative for anal fissure.

Non surgical therapy for anal fissure

BACKGROUND

Because of the disability associated with surgery for anal fissure and the risk of incontinence, medical alternatives for surgery have been sought. Most recently, pharmacologic methods that relax the anal smooth muscle, to accomplish reversibly what occurs in surgery, have been used to obtain fissure healing.

OBJECTIVES

To assess the efficacy and morbidity of various medical therapies for anal fissure.

SEARCH STRATEGY

Search terms include "anal fissure randomized".

SELECTION CRITERIA

Studies in which participants were randomized to a non-surgical therapy for anal fissure. Comparison groups may include an operative procedure, an alternate medical therapy or placebo. Chronic fissure, acute fissure and fissure in children are included in the review. Atypical fissures associated with inflammatory bowel disease or cancer or anal infection are excluded.

DATA COLLECTION AND ANALYSIS

Data were abstracted from published reports and meeting abstracts, assessing method of randomization, blinding, "intention to treat" and drop-outs, therapies, supportive measures (applied to both groups), dosing and frequency and cross-overs. Dichotomous outcome measures included Non-healing of the fissure (a combination of persistence and recurrence), and Adverse events (including incontinence, headache, infection, anaphylaxis). Continuous outcome measures included measures of pain relief and anorectal manometry.

MAIN RESULTS

21 different comparisons of the ability of medical therapies to heal anal fissure have been reported in 31 RCTs. Nine agents were used (nitroglycerin ointment (GTN), isosorbide dinitrate, Botulinum toxin (Botox), diltiazem, nifedipine (Calcium channel blockers or Cachablos), hydrocortisone, lignocaine, bran, placebo) as well as anal dilators and surgical sphincterotomy. When two studies are excluded from analysis due to quality concerns, the significance disappears in the three main analyses: GTN vs. placebo group (0.78; 0.56-1.08), in children (0.96; 0.48-1.92) and adults (0.73; 0.50-1.07). That is, GTN was, in this modified analysis, not significantly better than placebo in curing anal fissure. Cachablos were not tested against placebo, but in a comparison to GTN, Cachablo was equivalent in its ability to cure fissure (odds ratio 0.66; 0.22-2.01). Botox, in a meta-analysis of two studies compared to placebo, showed no significant advantage in efficacy (0.75; 0.32-1.77), and in a comparison to GTN analyzing two studies, was also not significantly better than GTN (0.48; 0.21-1.10).

REVIEWER'S CONCLUSIONS

Medical therapy for chronic anal fissure, acute fissure and fissure in children may be applied with a chance of cure that is only marginally better than placebo, and, for chronic fissure in adults, far less effective than surgery.

Botulinum neurotoxin and other treatments for fissure-in-ano and pelvic floor disorders

BACKGROUND

The management of disorders of the lower gastrointestinal tract, such as chronic anal fissure and pelvic floor dysfunction, has undergone re-evaluation recently. To a large extent this is due to the advent of neurochemical treatments, such as botulinum neurotoxin injections and topical nitrate ointment.

METHODS AND RESULTS

This review presents, inter alia, current data on the use of botulinum neurotoxin to treat lower gastrointestinal tract diseases, such as chronic anal fissure for which it promotes healing and symptom relief in up to 70 per cent of cases. This agent has also been used selectively to weaken the external anal sphincter and puborectalis muscle in constipation and in Parkinson's disease. Symptomatic improvement can also be induced in anterior rectocele by botulinum neurotoxin injections.

CONCLUSION

Botulinum neurotoxin appears to be a safe therapy for anal fissure. It is more efficacious than nitrate application and does not require patient compliance to complete treatment. While it may also be a promising approach for the treatment of chronic constipation due to pelvic floor dysfunction, further investigation of its efficacy and safety in this role is needed before general usage can be advocated.